Pressure infusion devices are known for infusing fluid under pressure such as whole or component stored human blood or intravenous fluid into a patient. Time can be very important when it is necessary to infuse a fluid under pressure into a patient. One of these devices is in the form of a bladder to which is secured netting. A fluid-filled plastic bag is positioned between the bladder and the netting and a bulb connected to the bladder is squeezed repeatedly until the required pressure of about 300 millimeters of mercury is reached whereupon the fluid in the plastic bag is infused under pressure into the patient. This device has certain drawbacks among which are:
THE PLASTIC FLUID BAG IS NOT EASILY POSITIONED BETWEEN THE BLADDER AND NETTING, THE BLADDER APPLIES PRESSURE AGAINST ONLY ONE SIDE OF THE PLASTIC BAG, THE NETTING IS NOT A SUBSTANTIALLY RIGID SURFACE AGAINST WHICH THE OTHER SURFACE OF THE PLASTIC BAG ENGAGES, IT TAKES ABOUT THIRTY TO THIRTY FIVE SQUEEZES ON THE BULB TO RAISE THE PRESSURE IN THE BLADDER TO THE REQUIRED LEVEL, AND THESE DEVICES ARE DIFFICULT TO SANITIZE.
Another pressure infusion device has a zipper to connect ends of a rectangular piece of material together to form a cuff. A bladder is encased in an enclosure member which is snapped into position on the piece of material. The liquid-filled plastic bag is placed on the bladder-contained enclosure member, the ends of the material are zipped together and the bladder is pumped with air to the desired pressure level. The drawbacks of this pressure infusion device are the same as those above.
A further pressure infusion device is disclosed in U.S. Pat. No. 3,565,292 which is mechanically operated by the controlled action of a piston applying pressure to the liquid-filled plastic bag. A crank is used to spring load the piston in order to provide the necessary pressure. The drawbacks of this pressure infusion device are:
IT TAKES CONSIDERABLE TIME TO CRANK THE PRESSURE TO THE REQUIRED LEVEL, IT IS MECHANICAL AND IT DOES NOT HAVE A PRESSURE GAUGE TO INDICATE THE PRESSURE BEING APPLIED ONTO THE LIQUID-FILLED PLASTIC BAG.